[Ultrastructural study of spermiogenesis in Acanthobothrium filicolle var. filicolle Zschokke, 1988 (Cestoda, Tetraphyllidea, Onchobothriidae)].

The spermiogenesis of the Onchobothriidae Tetraphyllidea A. filicolle filicolle is similar to that of the other Onchobothriidae. In this study, it is proved that: --the longitudinal displacement of the axonemes seen in the spermatozoon results from the sliding of one of the two axonemes during spermiogenesis. --the basal bodies and their attached rootlets which appear in the early spermiogenesis are enclosed within the spermatozoon body. --the crested like body indicates the extremity from which the spermatozoon detaches from residual cytoplasm. The origin of cortical microtubules and the gutter-like arranged ones near the axoneme, is discussed.